King County, WA

1,364 public highway bridges

King County Bridge Snapshot

King County, Washington contains 1,364 public highway bridges in the FHWA National Bridge Inventory. Roughly 31% are rated “Good,” 33.4% “Fair,” 3.3% “Poor,” and 3.3% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in WA are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

1,364

Total Bridges

31%

Good

3.3%

Poor

3.3%

Structurally Deficient

Condition Distribution

Good

31% (423)

Fair

33.4% (456)

Poor

3.3% (45)

SD

3.3% (45)

All Bridges (1,364)

Sort:

I-5

Over: NE NORTHGATE WAY

2.0 N JCT SR 522, King, WA

Built 1964 ADT: 45,581

I-5

Over: NE NORTHGATE WAY

2.0 N JCT SR 522, King, WA

Built 1964 ADT: 46,050

SR 18

Over: M STREET

0.6 E JCT SR 164, King, WA

Built 1984 ADT: 18,226

I-90 EB

Over: I-90 WB

JCT I-5, King, WA

Built 1988 ADT: 9,982

NE 51ST STREET

Over: SR 520

3.9 E JCT I-405, King, WA

Built 1987 ADT: 61,404

NE 4TH STREET

Over: I-405

2.4 N JCT I-90, King, WA

Built 1987 ADT: 9,639

I-90

Over: RAINIER AVE

0.6 E JCT I-5, King, WA

Built 1988 ADT: 28,381

CITY ST - 76TH AVE

Over: I-90

4.0 E JCT I-5, King, WA

Built 1989 ADT: 125,642

77TH AVE SE

Over: I-90

4.2 E JCT I-5, King, WA

Built 1989 ADT: 118,092

80TH AVE

Over: I-90

4.4 E JCT I-5, King, WA

Built 1988 ADT: 118,092

ISLAND CREST WAY

Over: I-90

4.5 E JCT I-5, King, WA

Built 1989 ADT: 118,092

EAST MERCER WAY

Over: I-90

5.7 E JCT I-5, King, WA

Built 1988 ADT: 123,219

NORTH MERCER WAY

Over: I-90

5.4 E JCT I-5, King, WA

Built 1989 ADT: 123,219

NE 4TH ST

Over: CITY STREET AND SBCD

2.4 N JCT I-90, King, WA

Built 1989 ADT: 16,919

SHOREWOOD DRIVE

Over: I-90

5.0 E JCT I-5, King, WA

Built 1989 ADT: 123,219

I-5

Over: METRO ACCESS

0.9 N JCT SR 523, King, WA

Built 1990 ADT: 1,144

66TH AVE S

Over: I-405

0.8 N JCT I-5, King, WA

Built 1990 ADT: 153,756

LIND AVE (88TH AVE

Over: I-405

1.1 N JCT SR 181, King, WA

Built 1990 ADT: 166,259

SE 180TH AVE

Over: SR 18

0.9 E JCT SR 516, King, WA

Built 1988 ADT: 36,767

SR 202

Over: SR 522

0.8 E JCT I-405, King, WA

Built 1989 ADT: 62,639

SOUND TRANSIT RAIL

Over: I-5 & CITY STREETS

JCT I-90, King, WA

Built 1991 ADT: 5,488

SE 28TH ST

Over: I-90 E-S RAMP

4.4 E JCT I-5, King, WA

Built 1992 ADT: 5,539

I-90

Over: CITY STREETS

0.1 N JCT I-90, King, WA

Built 1991 ADT: 27,000

NE 124TH ST

Over: RAMP/120TH AVE

5.5 N JCT SR 520, King, WA

Built 1990 ADT: 6,271

PEDESTRIAN

Over: RAINIER AVE S

0.6 E JCT I-5, King, WA

Built 1992 ADT: 28,381

I-90

Over: RAINIER AVE S

0.6 E JCT I-5, King, WA

Built 1992 ADT: 28,381

PEDESTRIAN

Over: SR 90 RAMP

0.7 E JCT I-5, King, WA

Built 1992 ADT: 8,799

E-E RAMP

Over: I-90, RAMPS, MERCER SL

6.4 E JCT I-5, King, WA

Built 1993 ADT: 68,450

S-E RAMP I-405

Over: SR 520

JCT I-405, King, WA

Built 1993 ADT: 64,231

E-N RAMP SR 520

Over: I-405 & SR 520

3.7 N JCT I-90, King, WA

Built 1993 ADT: 162,591

RENTON AVE S

Over: SR 405

0.9 N JCT SR 515, King, WA

Built 1994 ADT: 169,413

CEDAR AVE S

Over: I-405

0.8 N JCT SR 515, King, WA

Built 1993 ADT: 169,413

I-405

Over: SR 169

10.0 N JCT SR 18, King, WA

Built 1994 ADT: 39,269

I-90 RAMP

Over: MERCER SLOUGH, I-90

6.4 E JCT I-5, King, WA

Built 1995 ADT: 68,450

BICYCLE/PEDESTR.

Over: I-90 RAMP EB TO RAINIER

0.6 E JCT I-5, King, WA

Built 1995 ADT: 6,034

I-5 SBCD

Over: SR 104/205TH ST

1.2 E JCT SR 99, King, WA

Built 1995 ADT: 43,749

SR 18

Over: BNRR, AUBURN-BLK DIAMOND

2.3 E JCT SR 164, King, WA

Built 1995 ADT: 9,224

PEDESTRIANS

Over: SR 519

W END MARION ST, King, WA

Built 1994 ADT: 12,000

SR 520

Over: PKWY & SAMMAMISH RIVER

4.9 E JCT I-405, King, WA

Built 1995 ADT: 38,940

SR 520

Over: SR 202 & BIKE PATH

7.7 E JCT SR 522, King, WA

Built 1995 ADT: 35,875

ACCESS (AVONDALE)

Over: RAMP & NE 76TH

0.1 E JCT SR 520, King, WA

Built 1996 ADT: 16,261

SR 99

Over: DUWAMISH RIVER

0.1 N JCT SR 509, King, WA

Built 1996 ADT: 22,940

I-5 RAMP

Over: NORTHGATE WAY

2.0 N JCT SR 522, King, WA

Built 1995 ADT: 45,581

SE 188TH ST

Over: SR 18

4.0 E JCT SR 169, King, WA

Built 1996 ADT: 22,663

SR 18

Over: HOLDER CR HOBART RD

4.6 E JCT SR 169, King, WA

Built 1996 ADT: 8,691

I-5 HOV LANES

Over: I-405 NB, RAMPS

JCT I-5, King, WA

Built 1996 ADT: 36,699

E-N RAMP

Over: SR 900

JCT I-405, King, WA

Built 1997 ADT: 25,253

304TH ST

Over: SR 18

4.6 E JCT SR 164, King, WA

Built 1997 ADT: 54,920

SE 312TH WAY

Over: SR 18

3.8 E JCT SR 164, King, WA

Built 1997 ADT: 54,920

COVINGTON WAY SE

Over: SR 18

7.1 E JCT SR 164, King, WA

Built 1997 ADT: 28,822

Read our methodology — how this data is sourced, computed, and verified.

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Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainBridges Editorial

Reviewed byPlainbridges Editorial, Plain Bridges Editorial Team · June 6, 2026